It is often desired to provide systems for viewers which create for the viewer an artificial environment such that the viewer can be presented with created images, for example, of a particular geographical location. This type of system is known as an artificial, or virtual, reality system.
The main idea is to build three-dimensional models of different types of objects, such as buildings, architectures, wiring diagrams, frames of things, military installations, computer chips, and view these three dimensional models on a graphics display. The display can be helmet mounted with a heads-up display or could be an LCD display or could be projected on glasses. The main point being that the viewer's field of vision is limited to only the presented three-dimensional model. The viewer can only see a certain area, and if the viewer turns his/her head right, then the view of the model changes right. If the viewer looks left, then the view shifts to the left. This creates an artificial reality around the viewer.
Such systems exist, usually for military simulation networks and aircraft training. However, typically such systems are controlled by very powerful computers and processors which, in a typical system, can cost $250,000 each. In addition to being costly, such systems are not mobile and the user is confined to a stationary, or nearly stationary, position, in proximity to the controlling system.
The relative position and altitude of a person or object is important to monitor for many reasons. For example, in an artificial reality system, it is necessary to continually determine the direction a viewer is facing, the viewer's motion and the speed of the viewer's movements.
In the past, such measurements have been made using expensive, typically bulky, equipment.
In portable artificial reality systems, light weight and economy are mandatory since, in one embodiment, the viewer wears the directional sensor on a helmet, and in other embodiments carries the directional sensors in his/her hand.
Typically, such sensors are flux gate compasses, cameras, radio wave detectors and sensors, spring loaded acceleration devices, and other sophisticated devices, usually relying on magnetic flux detection or visual imaging. Also, usually such sensors require calibration each time a user begins a session using the device.
There are many situations in which full wrap-around sound is desirable for presentation to a listener. One such system is in artificial reality systems where an artificial environment has been created for a user. This environment would typically contain scenes that are created surrounding the viewer, and as the viewer moves in any plane relative to the environment, the scene changes as it would if the viewer were moving in a real environment.
In some situations sound is presented to the viewer in conjunction with the projected images such that as the viewer (or sound source) moves closer or further away, the sound will increase or decrease in volume and frequency. At times the sound would appear to come from directly behind, over or below the listener.
Conventional stereophonic speakers which are placed over each ear can only approximate the direction of the sound from one side or the other. These speakers are expensive and do not satisfy the requirement that the listener actually hear the sound coming from behind, above, below or from one side.
Currently, surround sound or holographic sound or what is called 3-D sound, is generated by using powerful digital signal processors which are basically stereo earphones tricking the ear into perceiving that the sound is coming from behind, around, or from different distances.
Accordingly, there is a need in the art for an artificial reality system which is self-contained and portable.
There is a further need in the art for such an artificial reality system which can provide created images depending upon the direction the viewer is facing and the movement of the viewer.
There is a still further need in the art to provide such a portable artificial reality system with images which are changing depending upon the direction the viewer is facing at any instant in time and also dependent upon the viewer's motion.
There is a still further need in the art for such a system which also provides sound keyed to the displayed image. Thus, there is a need in the art for a positional sensor which is self contained, light weight and economical to manufacture.
There is a further need in the art for such a sensor which allows for positional determination and velocity calculations while still remaining portable and reliable.
There is still a further need in the art for such a sensor which requires no calibration upon initial use and which is without mechanical moving parts.
Thus, a need exists in the art for a speaker system which is lightweight, inexpensive and yet which can create the illusion of sound coming from an omnipresent direction.
There is a further need in the art for such a system which can be created and controlled by an artificial reality system and is portable and generatable under processor control.